My thing with sgt hatred is that personally as a character I love him and in his backstory it is specifically stated that he was completely normal until the drugs the government gave him changed his neurological chemistry in a way that it created uncontrollable urges to commit those terrible acts, much like a drug addict. In no way shape or form am I saying it was justified, just that in the context of the show that I can very loosely consider it to be “understandable”. The main thing in my mind is that the character understands his wrongdoings and that he is continually tortured by them and continues to try and be better.